* {
  box-sizing: border-box;
}

body {
  background-color: #111;
  display: grid  ; 
  display: flex ;
  align-items: center;
  justify-content: center;
  height: 100vh;
  margin: 0;
}

.container {
  display: grid ; 
  display: flex  ;
  align-items: center;
  justify-content: center;
  flex-wrap :wrap  ;   
  grid-template-columns: repeat(20 , 1fr ); 
  max-width: 100%;
}

.square {
  background-color: #1d1d1d;
  box-shadow: 0 0 2px #000;
  height: 16px;
  width: 16px;
  margin: 2px;
  transition: all  2s ease-in-out;
}

.square:hover         {
  transition-duration:  0s  ;
}



